Resistance (MR) and Inductance (ML)

Been testing different settings and I’m using 0.05 MR and 15.0 ML. I can hear the motor whinning if ML is higher than 15 but to me the higher it is the better the feedback. Would like to know if there are any risks running ML at 15?

Hi Richard

What motor are you talking about?

The motor resistance and inductance are directly the P and I parameters to the torque tuning. Due to this, it’s best to use actual values. IONI can measure both, and it’s the suggested method for entering those values. If incorrect values are used, the motor performance will not be precise.

If the motor is very noisy, and very high torque bandwidth is not needed, then the ML and MR can be set lower.

More info can be found here:

Kind regards,

Hi, it’s a Mige 15015 22bit. I’ve tried the detecting option and find the feedback in iRacing just far to twitchy, oscillates too much with high resistance values. It may be a physics issue idk. Using 0.05 and 15 with 100Hz bandwidth filter works well. Not sure my wheel has velocity options under tuning, will have to check if there’s an advanced section.

High values directly affect the gain parameters in torque controller, making the overall gain of the compined PC - usb - SimuCUBE system too high, and making the system go unstable because of this.

Unfortunately this is a combination of things that we can mitigate via torque bandwidth, damping and friction, and usually no manual adjustment of ML and MR is required.

I’ll move this thread to SimuCUBE forum.

I did a good 30+ laps without problems last night. Just wondering if I risk damaging something?

I’ve never liked damping, feels too plasticy. Friction and inertia might be something to try though as there’s still some slight knockyness. I’m using irFFB with 60Hz 720, no reconstruction filter, 100Hz TBF everything else disabled, 65Nm max force and ~80% strength. I recommend trying it with iRacing, works well.

I would like to set the TBF to 60Hz actually to match iRacing’s output. Would it be possible to change it to a +/- option so I can set any specific value?

Not possible to do that without significant non-backwards compatible firmware changes for IONI drive. And not needed, as torque bandwidth has nothing to do with command update rate. Completely different things.

Right but it’s knocky and loose with anything more than 100Hz, I imagine 60Hz would sync better with iRacing’s physics. If it doesn’t take too much time, would it be possible to send me a firmware update for testing?

No. Torque bandwidth is not update rate.

To represent step changes, which all FFB signals are if one looks closely enough, we can talk about square wave which is a step change in its simplest form.

To present a perfect stepped change, it has to have unlimited number of frequencies, i.e a perfect square wave has infinitely high frequency content. This gif file I found shows how adding higher frequencies (on the right) makes the square wave more accurate:

But addition of these signals is imperfect, as there is the overshooting effect at each “corner”. Similar overshoot can happen, when the torque controller overshoots a bit (MR and ML quite high).

Therefore, there must be a low pass filter that filters some of these higher frequencies out. This picture is of a low pass filter, a bit extreme one, but as you can see, it can filter out the high frequency content and thus also any slight overshoots that the torque controller can generate.

You can still imagine the up - low - up - low commands being at, for example, 60 Hz rate, but with the signal having very high frequency content.

I have not ever tested lower than 680 Hz torque bandwidth, and I guess I would start to loose actual feedback detail when going much lower than that. I guess some people are sensitive to this, as they run unlimited TBW. I run at 2200 Hz at the moment.

If you are feeling any notchiness, then you are in fact still feeling these 60 Hz updates from iRacing, even if you do the interpolate to 720 Hz via IRFFB. It is not a perfect solution, and in fact can even go wrong sometimes. We should dedicate our efforts to try to convince iRacing to step up that rate to 360 Hz natively, it would be huge improvement.

Yes I agree. Higher frequencies work alright with reconstruction filter but I definitely feel more fidelity with irFFB and about the same level of latency which isn’t much. Ideally the output rate should be high enough not to need any kind of filtering but maybe it still will even with 360Hz. Feedback feels good for me atm but I can’t help but feel 60Hz TBF would be better than a 100Hz. I haven’t lost any detail because of irFFB. Wouldn’t mind trying 120Hz too as it might sync better, the knocks and cogs feel like random dissonance. Would be really great if I could set TBF to anything I want.

IRFFB does not add latency in its interpolated mode, that is true. It is about the same what the reconstruction filter does, I think, but the reconstruction filter does go to 2500 Hz instead of just 720 Hz. USB update rate maximum is 1000 Hz, and even at that rate, there will already be issues.

But these have nothing to do with the fact that you will start to lose detail when using more aggressive low pass filter. It might feel smoother, though.